Characterization of the Desmosome Protein Perp

描述（由申请人提供）：与称为桥粒的细胞-细胞粘附连接缺陷相关的人类疾病表明桥粒成分对于皮肤和外胚层衍生物（包括头发、牙齿、指甲和汗腺）的功能和维护的重要性。使用基因敲除小鼠，我们最近发现 Perp 四跨膜蛋白是 p63 分层上皮发育程序的一个组成部分，它在桥粒功能和皮肤上皮粘附中发挥着重要作用。作为关键的桥粒成分，Perp 失活可能导致外胚层衍生物功能障碍。为了解决这一假设，我们建议使用我们生成的条件小鼠来专门消除外胚层及其衍生物中的 Perp，并确定衰老成年小鼠中出现的表型。通过这一分析，我们将定义 Perp 在毛囊、指甲、牙齿和汗腺中的作用。由于桥粒在外胚层衍生物中的作用尚不清楚，我们的研究将为它们在这些情况下的作用提供新的见解。此外，揭示这些组织区室中 Perp 缺乏的后果为未来识别与 Perp 缺乏相关的人类疾病提供了基础。为了深入了解 Perp 在桥粒上的作用机制，我们将通过生成一组具有特定结构域改变的 Perp 突变体来定义 Perp 内的重要功能基序，并且我们将鉴定与 Perp 相互作用的桥粒蛋白。最后，我们建议研究 Perp 在桥粒动态组装和拆卸中的作用。为了确定 Perp 如何促进桥粒粘附，我们将确定 Perp 是否增强质膜上桥粒蛋白的运输、聚集或稳定性。为了确定 Perp 在各种生理和病理刺激（包括生长因子、创伤和寻常型天疱疮抗体）诱导的桥粒溶解中的作用，我们将检查这些环境中 Perp 的表达、定位和翻译后修饰。这些实验将深入了解 Perp 在发育、伤口愈合和癌症等过程中桥粒重塑中可能发挥的更大作用。总之，这些方法将帮助我们了解 Perp、桥粒和 p63 如何促进上皮完整性和外胚层附属物功能，以及它们的功能障碍如何导致疾病。

DESCRIPTION (provided by applicant): Human diseases associated with defects in cell-cell adhesion junctions known as desmosomes have suggested the importance of desmosomal components for the function and maintenance of the skin and ectodermal derivatives, including hair, teeth, nails, and sweat glands. Using knockout mice, we recently identified the Perp tetraspan membrane protein as a component of the p63 stratified epithelial development program, where it plays an essential role in desmosome function and epithelial adhesion in the skin. As a critical desmosomal constituent, Perp inactivation might lead to dysfunction of ectodermal derivatives. To address this hypothesis, we propose to use conditional mice we generated to ablate Perp specifically in the ectoderm and its derivatives and to determine the phenotypes arising in aging adult mice. Through this analysis, we will define the role of Perp in hair follicles, nails, teeth and sweat glands. As the role of desmosomes in ectoderm derivatives is not well understood, our studies will provide new insight into their role in these contexts. Moreover, revealing the consequences of Perp-deficiency in these tissue compartments provides a basis for identifying human diseases associated with Perp-deficiency in the future. To gain insight into the mechanism of Perp action at the desmosome, we will define important functional motifs within Perp by generating a panel of Perp mutants with alterations in specific domains and we will identify Perp-interacting desmosomal proteins. Finally, we propose to examine the role of Perp in the dynamic assembly and disassembly of desmosomes. To determine how Perp promotes desmosomal adhesion, we will establish whether Perp enhances trafficking, clustering or stability of desmosomal proteins at the plasma membrane. To define Perp's role in desmosome dissolution induced by a variety of physiological and pathological stimuli, including growth factors, wounding, and Pemphigus Vulgaris antibodies, we will examine Perp expression, localization and post-translational modification in these settings. These experiments will provide insight into a larger role that Perp may play in desmosome remodeling during such processes as development, wound healing, and cancer. Together, these approaches will provide an understanding of how Perp, desmosomes, and p63 contribute to both epithelial integrity and ectodermal appendage function, and how their dysfunction leads to disease.